This invention relates to para-ordered aromatic heterocyclic graft copolymers.
In general, the class of aromatic heterocyclic extended claim polymers are well known for their outstanding thermal, physical and chemical properties Considerable research has been directed toward using poly(p-phenylene benzbisazole) polymers as the reinforcing elements in polymeric composites. These polymers, also known as rigid-rod polymers, have a high modulus and high strength, and can act as reinforcing elements similar to the reinforcement provided by chopped fibers, but with the reinforcement taking place at the molecular level.
Helminiak et al. U.S. Pat. Nos. 4,207,407 and 4,377,546 disclose polymeric alloys comprising rod-like aromatic heterocyclic polymers and flexible, coil-like heterocyclic polymers. These alloys are prepared by first dissolving the rigid-rod and coil-like heterocyclic polymers in methanesulfonic acid (MSA).
Rod-like polymers are generally soluble only in strong acids and form lyotropic solutions in these solvents e.g. polyphosphoric acid and methanesulfonic acid, however, relatively few flexible, coil-like polymers can be dissolved or are stable in methanesulfonic acid. The rod-like polymers are generally infusible, i.e. they degrade before melting, thus preventing solid-state processing. What is desired are rigid-rod heterocyclic polymers which are fusible.
Accordingly, it is an object of the present invention to proVide rigid-rod heterocyclic polymers which are fusible.
Other objects and advantages of the present invention will be apparant to those skilled in the art from a reading of the following detailed description of the invention.